Chemical Vapor Deposition Growth of Large Single-Crystal Mono‑, Bi‑, Tri-Layer Hexagonal Boron Nitride and Their Interlayer Stacking

• Published in: ACS nano Vol. 11; no. 12; pp. 12057 - 12066
• Main Authors: Ji, Yanxin, Calderon, Brian, Han, Yimo, Cueva, Paul, Jungwirth, Nicholas R, Alsalman, Hussain A, Hwang, Jeonghyun, Fuchs, Gregory D, Muller, David A, Spencer, Michael G
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 26.12.2017
• Subjects: morphology; bilayer; hexagonal boron nitride (h-BN); chemical vapor deposition; Raman; trilayer; stacking
• ISSN: 1936-0851; 1936-086X; 1936-086X
• DOI: 10.1021/acsnano.7b04841

Two-dimensional hexagonal boron nitride (h-BN) is a wide bandgap material which has promising mechanical and optical properties. Here we report the realization of an initial nucleation density of h-BN <1 per mm2 using low-pressure chemical vapor deposition (CVD) on polycrystalline copper. This enabled wafer-scale CVD growth of single-crystal monolayer h-BN with a lateral size up to ∼300 μm, bilayer h-BN with a lateral size up to ∼60 μm, and trilayer h-BN with a lateral size up to ∼35 μm. Based on the large single-crystal monolayer h-BN domain, the sizes of the as-grown bi- and trilayer h-BN grains are 2 orders of magnitude larger than typical h-BN multilayer domains. In addition, we achieved coalesced h-BN films with an average grain size ∼100 μm. Various flake morphologies and their interlayer stacking configurations of bi- and trilayer h-BN domains were studied. Raman signatures of mono- and multilayer h-BN were investigated side by side in the same film. It was found that the Raman peak intensity can be used as a marker for the number of layers.